Istanbul (CNN)One of the world's most volatile regions was roiled further Tuesday when Turkey shot down a Russian warplane near the Turkish-Syrian border. Turkey said it hit the plane after it violated Turkey's airspace and ignored 10 warnings.
One of the two pilots was killed in the air by fire from the ground, according to Russia's state-run news agency RIA Novosti. The fate of the second pilot wasn't disclosed.
Meanwhile, a Russian marine was killed on Tuesday during an operation to rescue the two pilots,

The head of Nato said it stood in solidarity with Turkey as the Kremlin warned of "serious consequences".
US President Barack Obama has assured his Turkish counterpart, Recep Tayyip Erdogan, in a phone call of the support of the US for his country's right to defend its sovereignty.
The White House said both presidents had agreed on the importance of de-escalating the situation.
Turkey said the jet had strayed into its airspace but Russian President Vladimir Putin insisted the Su-24 had been hit by an air-to-air missile while flying over Syrian territory.